B015679 - PETROGRAPHY AND LABORATORY

Italian

This is an introductory course to the study of rocks and rocks-forming minerals. Igneous, metamorphic and sedimentary rock classifications will be defined in detail. The petrogenetic processes will be outlined as will in the frame of the general Earth dynamics.
The lab will lead the students to recognise and distinguish the different rock-forming minerals (mainly silicates) under the petrographic microscope and to the modal and chemical classification of rocks.

B. D’Argenio, F. Innocenti, F.P. Sassi (1994) Introduzione allo srtudio delle rocce, UTET, 162 pp. [ISBN 88-02-04870-3]. [only rocce sedimentarie]
John D. Winter (2010) Principles of Igneous and Metamorphic Petrology (2nd Edition), Prentice Hall, 720 pp. [ISBN-10: 0321592573/ISBN-13: 9780321592576]
R. W. Le Maitre, A. Streckeisen, B. Zanettin, M. J. Le Bas, B. Bonin, P. Bateman (2002) Igneous Rocks: A Classification and Glossary of Terms. Cambridge University Press, 2nd Edition Paperback [ISBN-13: 9780521619486]
Douglas Fettes, Jacqueline Desmons (2011) Metamorphic Rocks: A Classification and Glossary of Terms. Cambridge University Press. Paperback [ISBN-13: 9780521336185]
Michael M. Raith, Peter Raase, and Jurgen Reinhardt (2012, second edition) Guide to Thin Section Microscopy – Mineralogical Society of America, 127 pp. [ISBN 978-3-00-037671-9] – downloadable at http://www.minsocam.org
MacKenzie W.S., Donaldson C.H. & Guilford C. (1991) Atlas of igneous rocks and their texuters. Longman, England.
Yardley B.W.D., MacKenzie W.S. & Guilford C. (1990) Atlas of metamorphic rocks and their texuters. Longman, England.
- Handouts available during lessons

Knowledge of the classification of rocks forming our dynamic planet; Chemical-physical parameters of mineral equilibration in rocks; Genesis and differentiation of rocks in response to the dynamic processes active in the Earth interiors.
The aim of the laboratory is to teach the student the petrographic techniques to recognise and make a proper scientific classification of common geomaterials, by means of thin section analysis of rocks at the petrographic microscope

Principle of Chemistry, and inorganic chemistry; Principles of physics, mineralogy, and optic;

Theory will be furnished in classes that are supplemented by optical microscope training, laboratories, and field excursions.
Laboratory (3 CFU) will guide the student to thin section analysis with recognition of rock forming minerals and classification of igneous and metamorphic rocks.

The attendance to lectures is recommended, especially in case of laboratory activity.

The cultural skill will be checked though an oral colloquium after positive evaluation of a practical test on rocks description and classification in thin sections.

Introduction to petrography and petrology; Earth Interiors, Clarke chemical distribution; geothermobaric gradient of Earth; the rock cycle.
Igneous rocks: distribution on Earth; physical chemical parameter of magma and its rheology. Emplacement mechanisms of igneous rocks.
Textures of igneous rocks: quenching, nucleation and growing rates. Principles of optical mineralogy; rock-forming minerals and their optical characteristics; the use of the optical microscope and the thin sections;
Classification of igneous rocks: Streckeisen’s classification of igneous rocks; classification of gabbroid rocks; classification of ultramafic rocks; Total Alkali Silica diagram; C.I.P.W. norm; saturation in silica.
Principles of thermodynamics: enthropy, enthalpy, Gibbs free energy. Phase equilibria in igneous and metamorphic systems: Clapeyron law; Le Chateleier rule; Phase rule; unary, binary and ternary systems; partial melting and equilibrium crystallisation; congruent and incongruent melting; reaction points and eutectics. Phase diagrams: unary (H2O, SiO2); binary (CaMgSi2O6-CaAl2Si2O8; NaAlSiO4-SiO2; Mg2SiO4-SiO2; CaAl2Si2O8-NaAlSi3O8; KAlSi3O8- NaAlSi3O8); ternary (CaAl2Si2O8-CaMgSi2O6–Mg2SiO4; NaAlSiO4-CaMgSi2O6–SiO2; CaAl2Si2O8-Mg2SiO4-SiO2; NaAlSiO4-KAlSiO4-SiO2). Phase diagrams for basalts after Yoder & Tilley (1962, Journal of Petrology). Melting experiments on basalts and mantle compositions. The effect of P and PH2O on phase relationships in igneous and metamorphic systems. Genesis of magmas: partial melting due to decompression, slab dehydratation, plume upraise, continental collision.
Differentiation processes in igneous systems. The magmatic series.
Trace elements as tracers of petrogenetic processes in igneous systems; HFSE and LILE; batch and raleight melting, fractional crystallisation; REE and spiderdiagrams.
The oceanic magmatism (MORB & OIB), the orogenic igneous associations (CA); the alkaline and ultra-alkaline igneous associations; granites and their genesis.
The metamorphism: factors controlling metamorphic transformation (P-T-Fluid); metamorphic reactions and fluids (CaCO3 + SiO2 = CaSiO3 + CO2; KAl2Si3AlO10(OH)2 + SiO2 = KAlSi3O8 + Al2SiO5 + H2O); Pressure of H2O and lithostatic.
The metamorphic grade and isograde; metamorphic facies. Isochemical metamorphic groups, metamorphic type and processes; classification of metamorphic rocks. Textural transformations.
Contact metamorphism; Hydrothermal metamorphism Cataclastic metamorphism; Regional metamorphism: orogenic belts; accretionary prisms; subduction metamorphism. Partial melting and metamorphism: granulite, kinzigite, migmatite.
Metasomatism and the skarn.
Principles of sedimentary petrology. Folk’s classification of sedimentary rocks.
The aim of the course, an essential part of the geological culture, is to teach the student how to classify the most common geomaterials. This aim will be achieved throughout theoretical and laboratory lessons, and individual laboratory practice. Rock identification (natural or synthetic materials) at the microscope is fundamental in geological sciences, and will be joined by macroscopic study of hand-samples as well. The main arguments, which will be dealt with during the course, are: petrographic methods of analysis of geomaterials; basics of optical petrography and optical properties of minerals; structures and textures of common igneous and metamorphic rocks; modal and textural classification of igneous and metamorphic rocks; identification and recognition at the petrographic microscope of the mosto common igneous and metamorphic rocks.